According to the report, Russian Kh-101 airborne strategic missiles were used in the strike. While the effective range of the missiles is up to 2800 miles (4,500km), the strikes were conducted from a range of around 600 miles (1,000km). Missiles of this type can be fitted with nuclear warheads, after which they receive the Kh-102 designation.
Escorted by Su-30SM fighter aircraft based at the Khmeimim Air Base in Syria, the Tu-95MS bombers took off from an airbase near the southern Russian city of Engels and made their way to Syria after airborne refueling.
RT report found here.